Pennsylvania Corn: Herbicides and Rotation to Cover Crops

With silage harvest underway a number of farmers are considering cover crop establishment this fall. Remember that some herbicides can persist and potentially influence successful cover crop establishment.

Both the 2017/18 Agronomy Guide (Table 2.1-12) and the 2017 Mid-Atlantic Weed Management Guide (Table 1-6), contain a table titled Corn herbicide half-lives and their potential to injure fall-established cover crops that include the major corn herbicide restrictions and guidelines.

Remember that cash crop rotation restrictions may be due to the concern for herbicide residues accumulating in forage or feed rather than carryover injury. Cover crops that are not harvested can be planted after any herbicide program, but the grower assumes the risk of crop failure.

For a more complete listing, refer to the Penn State Agronomy Guide or the Mid-Atlantic Weed Management Guide.